Dear hygienic,
Thks for the reference. I recall you are very fond of this data source.
Personally I hv never searched for S.aureus in hand swabs however I hv now done some brief looking around on the net.
I regret that so far I hv not been able to find any support for the criterion in yr reference, or any other positive tolerance for that matter. The primary source quoted at bottom of yr reference contains no mention of this aspect AFAIK. Frankly, I hv no idea where this number “20” came from.
In contrast, all the references I found to interpretation of S.aureus in hand swabs used “detection” as a direct criterion of unsatisfactory hygiene, particularly for high risk products (which I understand is yr situation).
As 2 examples, can see these documents –
bb1 - assessing microbial performance FSMS systems.pdf 952.18KB
245 downloads
bb2 - EIC_guidlines.pdf 852.42KB
213 downloads
(pg 19)
And this comment –
2. Staff hygiene
Hand swabs are randomly taken from various food-handling staff members. Samples are
evaluated for the presence of Staphylococcus aureus and E.coli. The recovery of E.coli
indicates faecal contamination and means that staff have broken a basic hygiene rule,
like failing to wash hands after going to the toilet. Samples are also be tested for the
potential pathogen Staphylococcus aureus, which some people naturally carry and
which can cause a rapid form of food poisoning. (Due to the presence of large numbers
of natural, non-pathogenic bacteria on all peoples hands, there is no point in doing the
standard plate count).
bb3 - FOOD-CONSULTING-SERVICES-COMPANY PROFILE.pdf 222.59KB
116 downloadsAs a corrective action, the first attachment above offers some general comments. This extract is rather more tough.
bb4 - hand swab, S.aureus.png 98.65KB
43 downloads (
bb5 - CFA chilled foods, micro.testing and interpetation.pdf 572.3KB
147 downloads )
One other point to note is that the type of work may obviously influence the “ease” of maintaining clean hands or vice-versa. This is well data-demonstrated in the “sprouts” link of my previous post. (see the S.aureus detection frequencies for various food types etc, Table3)
Other swab interpretation data contrary (or otherwise

) to the above is of course only too welcome.
Rgds / Charles.C
PS - actually, i subsequently found this sort of opposing concept to above but I suspect this viewpoint is considerably in the minority for the "typical" hand -
hand swab 2, S.aureus.png 17.48KB
42 downloads(from "Technology of Cheesemaking")